1. Field of the Invention
The present invention relates to an apparatus for controlling an automatic transmission of an automobile and a method thereof, and in particular relates to apparatus and method of controlling gear changes in an automatic transmission of an automobile equipped with a route guidance system, in which road information obtained from the route guidance system is used for controlling the automatic transmission.
2. Description of the Prior Art
One example of a prior art apparatus for controlling gear changes in an automatic transmission of an automobile based on information obtained from a route guidance system is disclosed In Japanese Laid-Open Patent Publication No. HEI 6-272753, in which the gear change control apparatus controls gear changing operations to automatically change gears so as to be suitable for the present driving conditions, based on the information obtained from the route guidance system and road information which has been previously prepared. In this prior art, gear change control apparatus, a gear change table (gear change pattern) is quickly established so as to be suitable for the present driving conditions based on the information obtained from the route guidance system and the road information, and then appropriate gear changes (i.e., changes in gear ratio) are carried out in accordance with the established gear change table.
Another example of such a prior art gear change control apparatus is disclosed in Japanese Patent Publication No. 6-58141, in which gear change control for an automatic transmission is also carried out based on information obtained from a route guidance system and road information that has been previously prepared.
However, in these prior art apparatuses, gear changes are carried out based on the information on the present driving conditions of the automobile that is obtained from the road information related to the detected present position. For example, when the automobile approaches an upgrade, the gear change control apparatus begins operations to effect a change of gears at the point in time when the automobile enters the upgrade. Further, when the automobile approaches a curved section of a road, the gear change control apparatus begins operations to effect a change of gears at the point in time when the automobile approaches the curved section of the road. Therefore, these prior art gear change control apparatuses can not take anticipated changes in the driving conditions into account when carrying out such gear change control operations.